JP2532524Y2 - Key drive for keyboard instruments - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key driving device for a keyboard instrument, in which a white key actuator is arranged behind a white key front rail and a black key actuator is arranged behind a black key front rail. The key drive actuator has two types of characteristics, each of which is made uniform, and the key drive force required at the time of reproduction is reduced.

[0002]

2. Description of the Related Art Conventionally, as a key driving device for an automatic piano,
For example, one disclosed in Japanese Utility Model Application Laid-Open No. 63-187196 has been proposed. In this technique, a key drive actuator is disposed between the reed under the key and before the reed, and the key is lowered to reproduce and play. Specifically, this actuator is disposed at a position deeper than the front of the reed for the black key and closer to the inside of the reed, and pulls down a shutter hanging down on the lower surface of the key via a swing lever. It is impossible to arrange all the actuators for the white key and the black key in one row along the key arrangement direction because of the space limitation. Therefore, these actuators are used for the white key and the black key. Each of them was arranged in a staggered pattern.

[0003]

However, in such a conventional technique, it is necessary to prepare two types of actuators having different characteristics, that is, two types of white key actuators and two types of black key actuators. Therefore, its drive control has been difficult. In addition, the position where the driving force is applied to the key from each actuator is closer to the balance pin (fulcrum) than the position where the pianist presses the key (key tip). For this reason, improvement is still needed to reproduce the performance faithfully with the performance of the actual pianist. Further, since the power point is close to the fulcrum, a large force is required as a key driving force, and there is a problem that the load on the actuator is increased. Further, when the white key and the black key have different lower surface heights, it is difficult to adjust the mounting.

Accordingly, the present invention is simple in its control, capable of faithfully performing and reproducing the performance, reducing the driving force, and easily adjusting the key lower surface height. It is an object of the present invention to provide a key driving device for a keyboard instrument that can be attached and unitized beforehand.

[0005]

According to the present invention, there are provided a white key and a black key, each of which is arranged to be swingable around a predetermined fulcrum on a shelf, and a position which is separated from the predetermined fulcrum of the white key by a predetermined distance. A white key driving means which is arranged side by side in front of a white key reed for restricting movement of the white key in a plane along the upper surface of the shelf plate, and which swings the white key; Black key driving means which is arranged at a predetermined distance from the fulcrum along a front of a black key reed for restricting movement of the black key in a plane along the upper surface of the shelf plate, and swings the black key. And a key driving device for a keyboard instrument.

[0006]

In the key driving device for a keyboard instrument according to the present invention, the white key driving means are arranged in front of the white key reed, and the black key driving means are arranged in front of the black key reed. These have two kinds of characteristics as driving means, and their control is simplified. In addition, these characteristics can be approximated to the performance characteristics during normal performance, and faithful performance reproduction can be performed. Since the key driving force acts on the key at the key tip portion remote from the reed, the key driving force can be reduced when trying to obtain the same pushing force of the pen. Therefore, the load of the generated thrust as the driving means is also reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a key driving device for a piano according to an embodiment of the present invention. FIG. 2 is a plan view showing the arrangement, and FIG. 3 is a cross-sectional view showing a key descent state of the key driving device according to one embodiment.

As shown in these figures, the white key 11 and the black key 12 are swingable in the vertical direction with the balance pins 15 and 16 planted in the reed (balance rail) 14 on the shelf 13 as fulcrums. It is supported by. The tip of the white key 11 is vertically guided by a front pin 18 erected on a front rail (before the reed) 17, and its horizontal movement is also regulated by the front pin 18. Similarly, the black key 12 is guided vertically by a front pin 20 erected on a front rail (before the reed) 19, and its movement is restricted in the horizontal direction.
The front rails 17 and 19 are arranged at predetermined intervals in a substantially parallel manner along the key arrangement direction.

Here, on this shelf 13, each key 11,
In the position below the tip of 12 (key press by the player)
Electromagnetic solenoids 21 and 22 are provided respectively.
As shown in FIG. 2, these electromagnetic solenoids 21 and 22 are arranged in a line in the key arrangement direction (the frontage direction). That is, the electromagnetic solenoid 21 for driving the white key 11 is disposed between the front rail 17 for the white key and the front rail 19 for the black key, and the electromagnetic solenoid 22 for driving the black key 12 is used for the black key. Front rail 1
9 is provided adjacent to the first embodiment.

More specifically, these electromagnetic solenoids 21
Reference numeral 22 denotes an actuator unit that is held by a single holder case 23. The holder case 23 has two rows of grooves 24 and 25 that open upward in a U-shaped cross section, and a flat portion 23A between the grooves 24 and 25 is formed on the upper surface of the front rail 19 for the black key. It is attached by being fixed. Cylindrical coils 26, 27 are erected and held in the respective grooves 24, 25. These coils 26 are erected in a row corresponding to each white key 11 (FIG. 2). Similarly, the coils 27 are also provided upright in the groove 25 and arranged in a row corresponding to the black keys 12.

Plunger loose fitting holes (holes into which the plungers loosely fit) are formed in the axial centers of the coils 26 and 27, respectively.
The cores 28, 2 made of a magnetic material such as soft iron
9 is fixed. The upper surfaces of these cores 28 and 29 are formed in a dent-like concave shape, and have a flat bottom surface and a conical inclined surface.

On the other hand, plungers 31 and 32 are hung on the lower surfaces of the white key 11 and the black key 12 (the lower surfaces of the key tips) above the plunger play holes. The plungers 31 and 32 are disposed in the plunger loose fitting holes so as to be freely retractable. The distal ends of these plungers 31, 32 are connected to the cores 28, 29, respectively.
, That is, a truncated conical shape. That is, this tip portion is constituted by a flat surface having a constant diameter and a conical slope. Reference numeral 33 denotes an upper yoke disposed at the upper ends of the coils 26 and 27.

Therefore, in the electromagnetic solenoid 21 (the same applies to the electromagnetic solenoid 22), when the coil 26 is energized under the control of the controller, the core 28 is magnetized by the generated magnetic field, and the plunger 31 is attracted. As a result, the key 11 (12) swings downward, and its tip descends to the position shown in FIG. Thereby, an action (not shown) is driven, and an automatic performance (reproduction performance) is performed.

In this automatic performance, the key 11 (12)
The point of application of the driving force (pulling force) to the solenoid 2
1 (22) front rail 17 (1
8), that is, in the vicinity of the key pressed portion by the player in the normal performance, and the direction of the acting force is also reduced from top to bottom, so that the white key 11 performs the same movement as the actual normal performance. (Black key 12) can be performed, and its reproduction can be performed faithfully.

At this time, the electromagnetic solenoids 21 for the white key are arranged in a line, and the characteristics thereof can be made uniform, and the characteristics of the electromagnetic solenoid 22 for the black key can also be made uniform. Therefore, performance control by the controller is simplified. Specifically, the electromagnetic solenoids 21 and 22
Are arranged in a straight line, so that the balance pins 15 and 16 which are pivot points and the points of action of the key driving force (plungers 31 and 32)
Are located at the same distance from each other for all the white keys 11 and the black keys 12. Therefore, each key 11, 12
The key driving force can be uniformly applied to all the keys 11 and 12 without the necessity of correcting the key driving force or the like corresponding to the above.

Further, since the pulling-down force acts at a position far from the fulcrum (balance pin) 15 of the white key 11 (and the black key 12 as well), the applied force can be reduced according to the principle of leverage. As a result, the burden on the solenoid 21 can be reduced. Specifically, the current supplied to the coil 26 can be kept small. Therefore, heat generation from the coil 26 can be reduced.

At this time, as shown in FIG. 3, the plungers 31, 32 are immersed in the plunger loose fitting holes, and the tips thereof are opposed to the cores 28, 29 in the vicinity. As described above, since the plungers 31 and 32 are configured to be inserted into the plunger loose fitting holes, the entire key driving device including the solenoids 21 and 22 can be configured to be thin.

Also, as described above, the plungers 31, 32
Since the tip surface and the opposing surfaces of the cores 28 and 29 are formed by inclined slopes and have substantially the same shape, the gap (gap) between them can be reduced and the magnetic resistance can be reduced. Can be. Therefore, responsiveness at the time of starting the operation of lowering the white key 11 and the black key 12 can be improved. Then, the characteristic between the thrust (plunger suction force) of the electromagnetic solenoids 21 and 22 as the actuators and the plunger stroke can be smoothed. Further, when the plunger 31 (32) is fixed to the lower surface of the key 11 (12), the tip is made convex, so that the weight can be reduced.

Also, since the plunger of the electromagnetic solenoid is attached to the key, if counter balance is required, the same weight is used to attach the balance pin in the longitudinal direction of the key regardless of whether the key is white or black. All that is required is to attach them to the same position on the opposite side of the sandwich, and the attaching work is simplified.

[0020]

As described above, according to the key driving device for a keyboard instrument according to the present invention, the driving force required for driving the key can be reduced, and the load on the key driving device can be reduced. Can be. In addition, it is only necessary to control the driving for two kinds of characteristics, that is, for the white key and for the black key, and the control is simple. Also, the reproduction performance can be performed faithfully. Also, the adjustment to the key lower surface height is easy. further,
It can be attached before the reed to form a unit.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a key driving device according to an embodiment of the present invention.

FIG. 2 is a plan view showing an arrangement of an electromagnetic solenoid of the key driving device.

FIG. 3 is a cross-sectional view showing a key pressed state in the key driving device according to one embodiment.

[Explanation of symbols]

11 white key, 12 black key, 13 shelf board, 14 reed, 15 balance pin (fulcrum for white key), 16 balance pin (fulcrum for black key), 17 front rail (in front of white key reed), 19 front rail (Before reed for black key), 21 electromagnetic solenoid (white key driving means), 2
2 Electromagnetic solenoid (black key driving means)

Claims (1)

(57) [Scope of request for utility model registration] 1. A white key and a black key, each of which is swingably disposed around a predetermined fulcrum on a shelf board, and a position of the white key at a predetermined distance from the predetermined fulcrum of the white key. A white key driving means that is arranged side by side in front of a white key reed that restricts movement in a plane along the plate upper surface and swings the white key, and at a position separated by a predetermined distance from a predetermined fulcrum of the black key Black key driving means for juxtaposing the black key so as to swing the black key, the black key driving means being arranged along the front of the black key reed for restricting the movement of the black key in a plane along the upper surface of the shelf board. A key drive for a keyboard instrument.